Technical Field
The present invention relates to an image processor, photographing device, program, apparatus control system, and apparatus.
Description of Related Art
A stereo camera as a photographing device including two photographing units generates information for calculating a distance to a specific object such as an obstacle that is included in a subject. When such a stereo camera is mounted on a vehicle to work with a vehicle control system, the stereo camera detects an obstacle included in a subject located in front of a vehicle to be used for an avoidance operation in a vehicle.
The stereo camera simultaneously photographs the same subject by the two photographing units to generate the information for use in the calculation of the distance to the specific object based on a difference between subject images in the respective photographed images. When the stereo camera works with the vehicle control system, the stereo camera repeats the photographing and the generation of the information at predetermined intervals, and generates as a moving image a parallax image including the information regarding the distance to the specific object included in the subject in the photographed image. The vehicle control system detects a traffic lane or an obstacle with the parallax image to be used for avoidance control, for example.
In order to accurately measure a distance by the stereo camera, it is necessary to know relative positions of components of each photographing unit such as a photographing lens and an imaging element. However, minute deformation of the photographing device caused by temporal changes, temperature features, and the like is unavoidable. It is therefore a photographing device using an automatic calibration technique, which corrects deviation of a coordinate of a photographed image, in parallel with periodical operations has been known (for example, refer to Patent Literature 1, Japanese Laid Open Patent No. 2014-138331).
The photographing device described in Patent Literature 1 updates a coefficient of a correction equation for correcting the deviation of the coordinate multiple times, so as to avoid false recognition of an obstacle in a vehicle control system using a corrected photographed image even when the correction amount of the deviation of the coordinate of the photographed image is large. However, it is necessary to further improve the calculation accuracy of the distance to the obstacle.
For example, the false recognition of the obstacle occurs when timing of using the corrected photographed image by the vehicle control system coincides with timing of updating the coefficient of the correction formula.